Newtone offers 12-string versions of five of their acoustic, 6-string sets and one of their electric, 6-string sets – Master Class phosphor bronze, 80/20 bronze and nickel-plated steel (round cores), Electro-Acoustic (round cores and brighter acoustic sound), Heritage (round cores and low tension) and Nickel Masters (hexagonal cores and bright, electric sound).
Very important: To prevent string unraveling, only trim these wound strings after they are secured and tuned to pitch. Or you can bend the string sharply and trim between the bend and the short end of the string.